Changes syllabus date format to include year

fixes CNVS-14336

test plan:
   - Go to a course syllabus
   - Make sure there is at least one assignment with a due date
   - The date column should include day of the week, month, day, and
     year

Change-Id: Iae4cfec5fd401f32626e514e68f5071a67b374ff
Reviewed-on: https://gerrit.instructure.com/38971
Reviewed-by: Matthew Wheeler <mwheeler@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Janelle Seegmiller <jseegmiller@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>